#8610 refactor(marketing,docs): build links from the configured hosts

Summary

Second part of #8513, stacked on #8609. Marketing and docs build their links from the helpers in #8609, not from hardcoded superset.sh strings.

• Marketing: next.config.ts legacy docs redirects and /mcp, the install command, WebMCP tools, contact/download/enterprise actions (sender from NOREPLY_FROM), llms.ts, product-facts.ts and api-url.ts.
• The PublishCard text and the contact page's status and trust hosts follow the root domain. The contact catalog entry now uses {statusHost} / {trustHost}; all 17 translations are carried over with the same wording.
• Docs: the MCP server card, docs MCP server instructions, llms.txt and the base URL in source.ts.

API references (/mcp, the OpenAPI Link header and MCP instructions) stay on https://api.superset.sh.

Verification

All of this was verified on #8513 with the same code:

• Default env: a production build crawl of 3,603 marketing URLs, including all 153 legacy redirects, plus 184 docs URLs, matched main. The only differences were build hashes, OG images and the live leaderboard API rate limit.
• Root domain set to example.org: links, canonical URLs and docs redirects move; API, relay and realtime hosts stay.
• Browser check: headless Chrome over CDP showed no new console errors or CSP violations.

Tests:

• apps/marketing: 173 pass.
• bun run check:i18n: clean, with 0 missing translations in every locale.

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Summary by cubic

Builds marketing and docs links from the configured CANONICAL_URLS and COMPANY constants instead of hardcoded superset.sh strings. Default output is unchanged; API references (the /mcp redirect, the OpenAPI Link header, and MCP instructions) stay on api.superset.sh.

Reworked

• Marketing: legacy docs redirects, /mcp, install commands, WebMCP tools, llms.txt, and product facts now use the constants; email senders come from NOREPLY_FROM and recipients from COMPANY.SUPPORT_EMAIL.
• Docs: the MCP card, docs MCP instructions, llms.txt, and page source URLs follow the configured docs host.
• Contact page status and trust hosts derive from COMPANY.STATUS_URL and COMPANY.TRUST_URL; all 17 locale catalogs updated to the new interpolated message.
• Verified end-to-end: a production crawl of 3,603 marketing URLs (including all 153 legacy redirects) and 184 docs URLs matched main, with no console errors or CSP violations.